I'd try a MJLS for this. It will start out very neutral, but will beat into understable fairly quickly with use. It seems to stay at a nice understable sweet spot for a long time. With premium plastic you either have a disc that starts off too stable for what you want, or is too understable of a wing design to be as predictable as you want on the turn.

MVP Amp! I absolutely love it for 300 foot anhyzer lines, and it almost always flattens back out, unless you don't want it too, then you can make it turn way over. If you want a distance driver (amp is a fairway driver), try a tern. It basically flies like the amp for me, just 50 feet further.